darTZeel NHB-108 Model One power amplifier Page 2

Never operate the Hi/Lo switches when the amplifier is turned on. And never, ever switch on the NHB-108 when it's not connected to a loudspeaker.

That's about it for "need to know" information.

Oh wait—there's the whole "eyes" thing. Remember when I said that I thought the glowing power indicators and power switch inadvertently resembled a face? Apparently, Delétraz thought so too. He's named the power switch the Power Nose and the LEDs the Eyes.

With the power switch off, the NHB-108 remains in standby mode. The Nose toggles it into and out of standby, and the Eyes glow more brightly when the amp is powered up. (I anthropomorphized them, thinking they were dully pleading "Play me" when I had the amp in standby—obviously, I spend way too much time alone with my hi-fi.) The Eyes also pulse in time to the music, although the brightness shifts are more extreme at low volumes than when the amp is cranking. When all is right with the NHB-108, the Eyes glow with the color of the flesh of a winter squash; when the amp is driven into protection mode, they glow dull crimson.

What could trigger such a signal? Well, a short circuit at the speaker outputs, speaker impedances that are too low, DC output of 2V, an output-device anomaly, or DC leakage from the preamp on powering on or off. "This, by the way, is a useful 'tool' indicating that the preamp has a potential problem," said Delétraz with laconic understatement. Furthermore, he assured me, all of this monitoring circuitry is "completely kept outside the signal path, in order to preserve sound purity."

Delétraz freely admits that there's a downside to his obsession with "sound care": When an abnormal situation is detected, a crowbar circuit "brutally" (his word) shorts the power supply, melting the main fuse of the affected channel. Should that happen, as it somehow did after the amp was transported to John Atkinson's home lab for measurement after I'd completed my audition, changing the fuse is apparently a major production. (I forgot to send along the set of tools darTZeel includes with the amp, and which includes a special set of pliers that would have made changing the fuse simpler. Sorry, JA.)

On the other hand, a catastrophic speaker failure is a much bigger hassle.

An arrest of attention in the midst of distraction
If all of the warnings and explanations make it sound as though the darTZeel is demanding to set up, that's not particularly the case. Once you've determined that your speakers are an appropriate load (or set the internal impedance switch to match those in the 1–3 ohm range), it's pretty much set it, power it up, and forget it.

Well, perhaps not. That glass lid is not just visually transparent, but also allows the passage of RF. To some extent, that's the point—Delétraz didn't want a big ol' metal lid bouncing the power supply's own EMF back into the audio circuits. He says it makes things sound "fuzzy." It does mean that you need to take some care in placing the NHB-108 within your system so that the amp isn't too close to, say, your preamp's or CD player's power supplies. I thought the innards of the darTZeel were so attractive that I didn't want to hide it inside my equipment rack anyway, so it held pride of place out on the floor, where I could look at it.

Enforce attention, like deep harmony
Pretty is as pretty does, of course, and audio performance was where the NHB-108 proved absolutely gorgeous. I had the darTZeel in-house for an extended audition and got to try it with a broad array of gear—ranging from ambitious loudspeakers such as Stereophile's 2004 Joint Product of the Year, the Aerial 20T, to such modest models as the Canton Ergo 702 DC, and preamplifiers such as Conrad-Johnson's ACT2 and Blue Circle's BC3 Galatea Mk.II. I never had any problems mating the darTZeel to any of them.

If I had to reduce my review of the NHB-108 to a single word, it would be sweet—but that doesn't reckon with the amp's chameleonic nature. Every time I changed the associated gear, the actual sound of the system changed. That's the mark of a transparent component, of course—but each time I changed the associated components, I also thought I've never heard this sound better before—another sign of a truly exceptional component.

When John Marks heard that I had the NHB-108 driving the Aerial 20Ts, he sent me an e-mail: "Are you in love?"

Oh yes. That was a magical combination. The Aerial's extended bass response (deeper and more powerful in my room than in Michael Fremer's, apparently—but then I had the darTZeel and he didn't) informed me that this was an amp to reckon with. Telarc's recording of Mahler's Symphony 3 with Benjamin Zander and the Philharmonia Orchestra (Telarc CD-80599) pretty much put me through the wringer. Of course, the Mahler Third is full of itself (and of just about everything that can be thrown into a symphony), but that's the glory of this all-out rampage of a performance.

But if you're obsessive about dynamic range—and really, what are the chances a Stereophile reader will be?— this is the recording for you. The orchestral forces sound huge, and are nicely balanced against Lilli Paasikivi's solo voice and the Tiffin Boys' Choir (great job on the "bimm bamms," kids!). But, brass nut that I am, I was most knocked out by the trombone solos of Byron Fulcher, who encompassed the complete tonal range, from rude blaps to dreamy, creamy purrs. Trombone can be awfully close to a squarewave, so any system that captures the live sound of that instrument is getting things right, down to the most micro of microdynamics. Through the NHB-108 and Aerial 20Ts, this recording sounded alive.

Of course, with Mahlerian forces, one wants to hear effortless crescendos, sharp transient attacks (especially on those timpani), and a precise balance between nearfield and distant soloists. The darTZeel delivered on all counts, but most high-end amplifiers do those things well, even if few of them capture timbres as accurately as did the 108.

The darTZeel was also a whiz at soundstaging, easily the equal of any tube amp I've had around the house—ever. When I attend live musical events, or listen to components that don't excel at this quality, I tend to think that we audiophiles may overvalue soundstaging. Yet when confronted by a component that does it extremely well, I always seem to melt.

I suspect that, for me at least, it's lagniappe. If an audio component has timbre, transient reality, dynamic range, and a compelling presence region, I can forgo holographic soundstaging, because I'd rather listen to my music than look at it (metaphorically speaking). However, I'm also a greedy so-and-so; given my druthers, I want it all.

The NHB-108 had it all. I just reveled in its deep, encompassing soundstage.

Sera Una Noche's eponymous CD (M•A Recordings M052A CD) is one of my favorite demo discs, not least because of the way producer-engineer Todd Garfinkle has captured the sound of instruments and voice in a fairly reverberant hall (the music, too, is captivating). On "Nublado," Garfinkle has placed a clarinet (playing in its low, woody register) well into the room's acoustic, but it's the sound of the notes seeking the room's boundaries that absolutely floors me. The NHB-108 placed me in that room with such precision that I could almost hear those low notes creeping along the floor like fog, seeking out the walls in order to bounce quickly back toward the microphones.

Yeah, that's an overheated fantasy, but the darTZeel let me hear so deeply into the space and the recording that my mind's eye worked overtime filling in the details. Not that there will be many left to your imagination—most of them will be right there in front of your ears.

Compelled one's attention without losing one's respect
The darTZeel is pretty much sui generis—t'ain't nothing much like it out there. On the other hand, its strengths—transparency, phenomenal tonal accuracy, timing—reminded me of two of my favorite power amplifiers, the Ayre V-5x and the Linn Klimax Twin. I had neither on hand for a head-to-head comparison, but that's the playing field right there: an amplification device from Class A of Stereophile's "Recommended Components."

Those products also describe the darTZeel's limitations. Like the NHB-108, the Linn and the Ayre are both transcendent, no-limits products, but with the difference that they can be dropped into just about any hi-fi system. The darTZeel's greatest asset is also its biggest sticking point: It is a pure performance device designed without compromise. It delivers 100Wpc into 8 ohms. If you need more power than that, look elsewhere. If your speakers require major current swings or present radical impedance loads, the NHB-108 may react with "brutal" termination of its fuse. That's not exactly a shortcoming, as it also allows the NHB-108 to extract maximum performance within its operational parameters.

As they say in the Silicon Valley, that's not a bug, it's a feature. Really. Accept the premise and you accept its limitations. In this case, the "limitation" is that you can get phenomenal performance if you play by the darTZeel's rules.

I could live with that.

The question is, could you?

If you're willing, and if the health of the Swiss franc vis-à-vis the dollar isn't too extreme a sticking point, the darTZeel NHB-108 Model One power amplifier is an audio component to reckon with. It's handbuilt, and that always costs a packet—at the moment, $18,181. I can't indulge in handmade watches, high-performance automobiles, or just about anything else that's actually made to order, but that doesn't mean I don't appreciate the level of craft involved. Like those luxuries, the NHB-108 is a work of art painstakingly and individually assembled from raw components. There's a lot to be said for economies of scale—economy, for one thing—but there's no denying that there's something special about anything as lovingly constructed as the NHB-108.

And, of course, there's its performance, which is quite simply remarkable. I've already said that it belongs in the company of the components in Class A of "Recommended Components," but that almost seems faint praise. Perhaps we should establish a super-category: "Components I Would Run Off to a Tropical Island With."

Nah. I guess I'll simply have to leave it at this: You have got to hear what this amp can do.

US distributor: Blue Light Audio
2725 SW Sherwood Drive
Portland, OR 97201
(503) 221-0465
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